After patch 1.4 the Thalmor Embassy Stone of Barenziah was removed from my inventory, I learned I could re-aquire from the Reeking Cave. The stone was not there. I then used a horse to jump over the Embassy fence, to see if it was in its original location (pre-1.4), it was not there either. I have kept track of which stones I have, which ones I dont, and the locations which I found them. It would seem that the updated Thalmor Embassy Stone is the only one unaccounted for. Does anyone know what the problem is and how I can aquire the missing/another/extra Stone on the 360? Otherwise I fear I will never be able to complete the quest, No Stone Unturned.

The Stone of Barenziah from the Thalmor Embassy was moved to the cave escape route you used, Reeking Cave. The entrance to the cave (aka how you escaped in Diplomatic Immunity) is just north of the embassy. The stone itself is near a dead mage, near the trap door back up to the embassy dungeon.

recheck every location. This happened to me, and I found the stone I was missing had returned to the spot it came from. For me it was in a house in windhelm. I've also seen on the wiki that a stone sometimes appears in the strange museum in windhelm, cant remember the name of the guy that owns it. If you still cant find it, then you may be screwed.